assembly instructions were posted for free on the internet so someone like paul mccarthy in marblehead, massachusetts, could print the idea. he took the idea to his son. i >> i thought he was a little crazy. he said we could print the fingers and clip them in. it was too much. >> reporter: the first time you saw it and tried it out -- >> it was pretty awesome. >> it's the most rewarding thing. >> what an amazing dad. how much do the hands cost? >> the hand costs 25 bucks but the printer costs $2,500. it was paid for by the school. he's on the fourth version and it's called the cyborg hand. >> what happens next? >> very interesting. i spoke the dad. leon is teaching the other kids to design and make these. their plan is to design them for kids locally, be able to give them to them and eventually go have lower rates of obesity. what'smore what's more the study found when families eat anywhere but the kitchen or dining room both parents and kids have a higher incident of weight problems. what's the whole equation? >> you're talking to each other and eating mindfully as opposed to the mindless eating in